Sanitary sewer systems generally include a series of manholes that are connected by sewer pipes to move waste water from sources to a sanitary treatment site. These manholes are most often constructed of concrete or block material and are conventionally shaped of cone, corbel, and bench sections. Such a manhole is shown in U.S. Pat. No. 4,957,389. Typically, the manholes are placed one thousand or more feet apart and are connected by the sewer pipes. They are four to five feet in diameter, and each is large enough to admit a maintenance worker into its interior. Additionally, a clean-out pipe is often connected to sewer pipes if the manholes are spaced unusually far apart. The clean-out pipe is connected to the sewer pipe and angled upward to ground level. The clean-out pipe can be opened at ground level to provide access to the sewer pipes for cleaning.
As described in U.S. Pat. No. 4,957,389, the manhole often requires a device installed in the manhole to catch water that flows into the manhole from ground level. The water can also flow in from many places, including cracks in the cone and corbel. The cracks are caused by shifts in the surrounding ground, temperature changes that affect the cement, and wear from auto traffic, and so forth. The cement of the manholes is also susceptible to disintegration from acids created in the sewer system.
Reinforced, preformed, plastic casings have been used to replace the concrete manholes. The plastic casings purportedly cost less and eliminate some of the problems found in the concrete manholes. For example, they are less affected by temperature changes, they generally do not crack, and they are impervious to acids in the sewer system. U.S. Pat. No. 3,938,285 discloses a two-piece, preformed, dome-shaped manhole casing that is to be placed below ground. It has cutouts at its bottom end that slip over sewer pipes that are in the line of the series of manhole locations. The size of the casings make them expensive to ship, and each casing may not match the requirements of the site terrain where it is to be installed. Additionally, the casing has to be sealed at the bottom to prevent leaks.
Other preformed casings have been suggested to overcome problems associated with installing a one piece, plastic manhole casing. The other suggested casings are segmented in various ways to be assembled and installed at the site. See for example U.S. Pat. Nos. 4,089,139, 4,255,909 and 4,275,75. These suggest preformed casings. While these casing are less expensive to ship, they are labor intensive at the installation site. They have a single input and output that are of standard size for sewer pipe in line at the sites.
The segmented and slotted casings are prone to leak and may float if installed in an area with a high water table. Most of these preformed casings are constructed of a cone, corbel, and bench in the manner of a concrete manhole. If the casing leaks, water may destroy the complete installation. Unless the casing is securely placed on a concrete foundation and surrounded by a fill material, a high water table can cause it to float and break the connections to input and output sewer pipes.
Consequently, it is not always economical to install a manhole of concrete or preformed plastic into which a maintenance worker can enter. Rather, a less expensive, more easily maintained waste water access fitting can be installed to access the waste water to the sanity sewer system. The fitting can be placed as the last or dead-end connection of the series of manholes, or it can be placed to access several homes in a cul-de-sac to the sanity sewer system. Additionally, the fitting can be placed between manholes to provide entry into the connecting sewer pipes for cleaning the sewer pipes more effectively than the smaller clean-out pipes that extend from ground level to the connecting sewer pipes.
The waste water access fitting can be made of preformed plastic, polyethylene, or a similar material. It is formed in a shape to be placed below ground to connect the waste water sources directly or indirectly to the sanitary sewer system. It is impervious to acids in the sewer system, and it need not be large enough for a person to enter into its body cavity for maintenance. However, it is large enough to admit equipment into its inner body for maintaining the connecting pipes, that is, equipment to clean out the pipes or admit TV cameras to inspect the pipes. It is watertight and may have waste water connections that receive water into its inner body from several sources and access the waste water to the sanitary sewer system through an output pipe. The waste water access fitting is placed below ground and held in position by granular fill dirt, and does not require a cement foundation as a mount. It is not a manhole. Rather, it supplements a manhole by accessing waste water to the sanitary sewer system.
Therefore, an object of my invention is to provide a waste water access fitting of a preformed, one-piece body that is smaller than a conventional manhole used in sewer systems. It is water tight and placed below ground with access to its inner body at ground level. It connects to waste water sources and a sanitary sewer to access the waste water to the sanitary sewer system while providing entry to its inner body from ground level for maintenance.
Another object of my invention is to provide a preformed, one piece, watertight waste water access fitting that is placed below ground to connect with sewer pipes in a series of manholes in a sanitary sewer system. The fitting is connected between manholes and has access from ground level to permit maintenance of the sewer pipes.
It is also an object of my invention to provide a preformed, watertight, one piece waste water access fitting that is placed below ground level to connect waste water sources to a sanity sewer system to accept and distribute waste water to the sanitary sewer system. The fitting is placed below ground and includes an extension that can be extended from the fitting to ground level to provide entry in its inner body from ground level